Questions on Singapore Auxiliary Minesweepers used in 1941

From the Washington Naval Treaty to the end of the Second World War.
Fatboy Coxy
Junior Member
Posts: 13
Joined: Thu Jul 19, 2018 5:18 am

Questions on Singapore Auxiliary Minesweepers used in 1941

Post by Fatboy Coxy » Tue Aug 07, 2018 6:33 am

Hi all

I have a number of questions regarding the Singapore Auxiliary Minesweepers used in 1941

With the Far East being a backwater, no purpose-built minesweepers were deployed there until the Bathurst class of Australian Corvette, a Minesweeper/Anti-Submarine ship came off the slips. So along with pretty much everywhere else, auxiliary ships were requisitioned by the Royal Navy and modified as minesweepers. The main threat was considered to be the German Auxiliary Raiders, cruising in the Indian Ocean, which might mine the Malacca straits, the main seaway to Singapore.

The Singapore auxiliary’s can be put in two groups, size wise. Half a dozen or so of about 450-700 tons, small coastal steamers, and about a dozen 200-250 tons, whalers, trawlers and harbour tugs. So now my questions start.

What minesweeping methods could these ships employ. I’ve read conflicting articles on whether smaller ships, 200 tons, are able to pull a contact sweep, with an Oropesa. Do we suppose they would have to work in pairs, pulling a sweep between them? With regard to distance sweeping, again they might have to work in pairs, but would they need a diesel generator added to power the sweep, if so how big an impact would its installation have on these ships.

The British Ham class inshore minesweeper introduced in the mid 1950’s was on a similar size; however, these were purpose built, and their top speed of 14 knots indicates they had the power to pull a sweep at 9 knots. They also were able to generate enough power to do distance sweeping, dealing with the magnetic and bottom mines.

Secondly, again dealing with the smaller vessels, where could they be employed. The Ham’s were for rivers, harbours, estuaries etc, which Malaya/Singapore had plenty of, but the main perceived threat was the Malacca Straits, where the method of delivery of the mines would be roll off the German Raider, and not air dropped, as was happening around Britain. This would suggest their use would be very limited if they couldn’t work in the straits.

Onto the larger ships, which are comparable in size to the Naval Trawlers and smaller minesweeper sloops, I think they may have had enough power to pull a Oropesa sweep, but their average speed was about 10 knots, so I’d guess a reduction of a couple of knots, say they sweep at 8 knots as a group, does that sound reasonable?

Again, for them, the additional power for the distance sweep is problematic, they may also need additional power generators.

A further question is, given that the range of build for these ships is from about 1910 to 1930, many if not all would be coal fired. When might be a reasonable date to see new commercial vessels built as oil fired. How far back would they go to convert from Coal to Oil, given the cost outlays in changing boilers, bunkerage to tanks, pumps and new boilers.

Lastly, armament, guns were in short supply, ships limited in what could be added, I presume they might all be reasonably armed with 1-2 Lewis guns, or would they be so desperate as having only rifles, for mine detonation.

Sorry guys, I know I sound a bit like an anorak, but there they are!